Apparatus for electrocoating conductive articles including magnet means to convey the articles

ABSTRACT

Apparatus is provided for obtaining the electrical deposition of a protective coating onto the surface of electrically conductive, magnetically-attractable metal articles. With the apparatus, a multitude of various articles, e.g., screws, clips, bolts, nails and the like, which may be in mixture, can be readily and efficiently coated in batch or continuous operation. The apparatus includes stationary magnet means in close proximity to a coating bath and having sufficient magnetic field strength to affect the location of coated parts in at least a zone of the coating bath. This stationary magnet means is together in assembly with rotatable, i.e., movable means, e.g., a drum member housing the magnet means. The rotatable means has a face element at least partly immersed in the bath. In rotation, this element provides for movement of articles within the bath while they are held under the influence of the magnetic field.

United States Patent Nessar Aug. 5, 1975 ARTICLES Inventor: Joseph D.Nessar, Painesville, Ohio Assignee: Diamond Shamrock Corporation,

Cleveland, Ohio Filed: June 18, 1973 Appl. No.: 371,149

[52] US. Cl. 204/300; 204/181; 204/201 [51] Int. Cl. B01k 5/02; C23b13/00 [58] Field of Search 204/181, 201, 203, 297 M,

[56] References Cited UNITED STATES PATENTS 1,168,281 l/l9l6 Buch204/297 M 2,047,418 7/1936 Kronsbein 204/297 M 2.133.324 10/1938Hosdowich 204/201 2.863.550 12/1958 Hommel 198/25 3,616,392 10/1971Haney 204/181 FOREIGN PATENTS OR APPLICATIONS 1,935,117 l/l970 Germany198/25 1 I I l Primary Examiner-John H. Mack Assistant Examiner-W. 1.Solomon Attorney, Agent, or Firm-John J. Freer [5 7 ABSTRACT Apparatusis provided for obtaining the electrical deposition of a protectivecoating onto the surface of electrically conductive,magnetically-attractable metal articles. With the apparatus, a multitudeof various articles, e.g., screws, clips, bolts, nails and the like,which may be in mixture, can be readily and efficiently coated in batchor continuous operation. The apparatus includes stationary magnet meansin close proximity to a coating bath and having sufficient magneticfield strength to affect the location of coated parts in at least a zoneof the coating bath. This stationary magnet means is together inassembly with rotatable, i.e., movable means, e.g., a drum memberhousing the magnet means. The rotatable means has a face element atleast partly immersed in the bath. In rotation, this element providesfor movement of articles within the bath while they are held under theinfiuence of the magnetic field.

17 Claims, 7 Drawing Figures k Rx 8 8,151 PATENTEUAUE 5MB 9 SHEET 1PATENTEU AUG 5 SHEET Fig.3

Fig. 4

PATENTED 5975 151 SHEET 3 PATENTED AUG 51975 SHEET Fig. 7

APPARATUS FOR ELECTROCOATING CONDUCTIVE ARTICLES INCLUDING MAGNET MEANSTO CONVEY TI-IE ARTICLES BACKGROUND OF THE INVENTION The deposition ofan organic coating by electrical de position processes on electricallyconductive articles has received much attention in recent years. Some ofthis attention has been focused upon the coating of large numbers ofsmall objects. One attractive feature of such a coating system, whichmay be termed electropainting, electrocoating or the like, is thegenerally desirable uniformity of coating.

Such coating uniformity is often difficult to achieve on small objects,as for example, screws, since they have sharp edges and abrupt changesin surface configuration that do not lend themselves to achieving auniform surface coating. In the coating of such small objects byclectrodeposition there has been tried the conventional coatingprocedure of placing many such items in a wire basket or similarconductive container. lt was early appreciated that such method involvescoating of the container during coating of the small items containedtherein. This results in disposing of the container after merely one useor of the economically unattractive removal of the coating from thecontainer before re-use.

It was therefore suggested to provide electrical connection between theobjects to be coated and the container with a disposableconnector-conductor, e.g., a layer of steel wool on the containerbottom. For example, in US. Defensive Publication No. T856,035, suchconcept has been suggested after a discussion of the above notedproblems associated with simply using wire baskets as coatingcontainers. The concept of employing steel wool simply supplants onedisposable item coated during the electrodeposition operation foranother disposable item.

Such disposable items cam be minimized; in the coating of small objects,this has been disclosed in US. Pat. No. 3,575,832. It has likewise beendiscussed in such patent the desirability of employing electromagneticsupport means. And, by such support means, the small objects, anddisposable connector-conductors, can be carried through not only thecoating but also the curing step, although simultaneous coating of aplurality of objects is not ostensibly a practical feature of suchoperation.

As has been mentioned hereinabove, the difficulty in obtaining a uniformcoating for many small objects is associated with the surfaceconfiguration of such objects. These configurations present a non-smoothappearance, but this feature may enhance the small objects makingcontact through deposited, wet coatings to an underlying electrode.Regardless, although paint films that are deposited by theelectrocoating process are self-limiting", at this resulting thicknessconductivity of the deposit is retained as long as the coating is wet.Thus, parts deposited on the coating will have impressed upon themsufficient flow of electrical energy to themselves become coated. Theself-limiting feature provides that the underlying article no longer issufficiently conductive to achieve a further deposition of paint onitself once a sufficient paint film thickness has been achieved.

Although both anodically depositable and cathodi cally depositablepaints can be formulated. and are contemplated for use herein,commercial development has focused upon anodically depositable paintsand such are often used herein for illustration although both types arecontemplated.

Movement of small articles during the coating operation is encouraged toachieve efficient coating; but since foaming of such baths may become aproblem, suppression of foam generation must be kept in mind. Forexample, in US. Pat. No. 3,616,392 there is disclosed an electrocoatingprocess employing a series of two conveyors, each conveyor being inassociation with a plurality of hoppers. Loading of parts into hoppersof the first conveyor, and subsequently dumping from same into thehoppers of the second conveyor, ostensibly permits adequate movement ofthe parts to obtain desirable coating thereon. The angle of the secondconveyor then permits the coated parts to be conveyed out of the coatingbath for subsequent curing. Such operation is not however simplistic innature, involving many moving parts, and necessitates a large tank and aconsiderable bulk of apparatus, when considered in association with thesize of the objects to be coated. In regard to this, and other aspectsof the foregoing discussion, reference can be had to Products Finishing,February, 1973, pages 34-43.

SUMMARY OF THE INVENTION An apparatus is now provided whereby many smallarticles can be easily and contemporaneously electropainted in batch orcontinuous operation. The apparatus istailored towards simplisticoperation and suppressing foam generation; and, it is directed to thetreatment of magnetically-attractable as well as electrically conductivearticles. With this apparatus, and thus with the method of the presentinvention, such small articles are quickly and efficiently electrocoatedand often with minimal equipment and further, while reducinguneconomical liquid drag-out losses.

The present invention is thus directed to apparatus wherein contact isestablished, and then interrupted between a plurality of discrete,magnetically-attractable and electrically-conductive metallic articlesof manufacture and electrically deposited coating composition; andfurther whereby applicator means brings into surface-coating contactelectrically charged articles and the coating composition, whiletransporting means carries wet, surface-coated articles away from thecoating composition. By this invention such apparatus also includesmagnet means proximate to the applicator means and arranged in closeproximity to the path of travel of the articles in contact with thecoating composition, establishing a magnetic field acting on wet, coatedarticles and thereby influencing such path of travel. This magnet meanscooperates with rotatable means that in rotation offers a face elementin continuous exposure to the coating composition and provides movementof wet, coated articles within the coating composition while thearticles are under the influence of the magnetic field.

In another aspect, the invention is directed to a method forelectropainting small articles. In yet another aspect, the invention isdirected to the method of preparing a multitude of objects forsubsequent electrodeposition of an organic film thereon, as well as tosuch clectrodeposition.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical cross sectional view of apparatus according to theinvention and having a rotatable drum with interior magnet assembly.

FIG. 2 is a vertical cross sectional view of apparatus employing a traycoating tank as well as a rotatable drum with interior magnet assembly.

FIG. 3 depicts a two-drum, vertical cross sectional view of apparatusaccording to the present invention and having a conveyor member around adrum type magnetic assembly.

FIG. 4 is a cross sectional view in vertical perspective of an assemblyfor carrying on surface pretreatment and subsequent electropaintingoperation.

FIG. 5 is a vertical cross sectional view of apparatus wherein a dualrotatable drum assembly enhances small part movement during coating.

FIG. 6 is a cross sectional view in vertical perspective of an assemblyusing a rotatable drum for part movement and in association withconveyor means.

FIG. 7 depicts in a cross sectional view an assembly of a coating drumplus a rotatable magnetic drum.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a drum orcylindrical shell 4 made conventionally of non-magnetic as well asnon-magnetizable but electrically conductive metallic material, ismounted by a hub 5 for rotational movement about a stationary shaft 6.The shaft 6 is usually mounted on bearings, not shown, supported on aframework, also not shown. Furthermore, the drum 4 is rotated inoperation as depicted in FIG. 1 in a counter-clockwise directiontypically by connection with a power source, all not shown. Within thedrum 4 is a stationary magnet 12 positioned by means of support membersnot shown. The magnet 12 has an outer, arcuate surface in closeproximity to the inner surface of drum 4 and spaced apart therefrom inconcentric relationship.

The bottom portion of the drum 4 is slightly immersed in a bath 11 ofelectrocoat paint contained in a holding tank 9. The tank 9 is locatedunder the end section of a chute 8 down which fresh articles 7 forcoating may be conveyed toward the bath 11. On the side of the holdingtank 9 opposite the end section of the chute 8, and closely adjacent tothe drum 4, is a conveyor 14. On the conveyor 14, coated parts 13 areconveyed away from the drum 4 and over a demagnetizer 15. Near the upperopen end of the holding tank 9 and immersed in the bath 11 is anelectrode 16 insulating layer on the upper surface thereof.

In operation, small fresh parts 7 are gravity fed from a source notshown down the chute 8; as such articles 7 leave the chute 8 they areattracted to the outer surface of the drum 4 by the magnet 12. In thisoperation where the bath 11 is an anodically deposited organic material,the drum 4 serves as the anode from a source of electric current, notshown, and is thereby connected to such source by means not shown, e.g.,by a brush-type contact. Drum 4 will thereby have deposited on its outersurface a soft, self-limiting layer of electrodeposited paint. As thedrum 4 rotates. such wet layer of paint, not shown. will be continuouslyair exposed and then re-immersed and wetted in the bath 11, maintaininga wet, deposited film.

Continuous rotation of the drum 4 permits parts 7 directed to the outersurface of the drum 4 to move initially through the bath 11 for coatingthereon; and, subsequently, while maintained under the influence of thestationary magnet 12, to be conveyed out of the bath 11. This path oftravel is continueduntil gravitational force overcomes the magneticfield. As a result, coated parts 13 fall, typically accompanied byinitial slipping across the face of the drum 4, and eventually away fromthe drum 4 onto the conveyor 14. The coated parts 13 are thereonconveyed away from the drum 4 over the demagnetizer 15 for removing anymagnetic effect imparted to the coated parts 13 under the influ-' enceof the magnet 12. Such coated parts 13 are transported on the conveyor14 typically to rinsing and curing means, not shown.

In FIG. 2, fresh parts 21 feeding from a source not shown enter a bath22 of electrocoat paint. The bath 22 is maintained in a tank 23.Submerged parts 20 in the bath 22 may move along the tank 23, e.g., thetank 23 may be a vibrating tray having attendant vibrating means notshown. During such movement, the immersed parts 20 come between thebottom of the tank 23 and an electrode 24 connected to a power source,not shown. The electric charge is given to the immersed parts 20 throughthe tank 23 and connected in conven tional manner to a power source. allnot shown.

As movement continues, resulting coated parts 25 come under theinfluence of a magnetic field originating with a stationary magnet 26positioned inside a pickup drum 27. The pickup drum 27 rotates inclockwise direction on a hub 28 around a stationary shaft 29. This hub28 and shaft 29 arrangement has attendant bearings and has attendantmeans connected with a power source. all not shown. The lower portion ofpickup drum 27 is immersed in the bath 22 of electrocoat paint.

The coated parts 25 under the influence of the mag net 26 are attractedonto the pickup drum 27 and by rotation of the drum 27 these parts 25are carried out of the bath 22. Subsequently. the parts 25 on the drum27 rotate away from the influence of the magnetic field and fall bygravitational affect to a conveyor 31. On the conveyor 31 the coatedparts 25 are then conveyed away and over a demagnetizer 32, typically torinsing and curing operations not shown.

In FIG. 3 a pickup drum 41 is supported by a hub 42 on a stationaryshaft 43. The drum 41 and hub 42 are supported on the shaft 43 bybearings, not shown; and, as with the drum 4 in FIG. 1. the pickup drum41 is driven by attendant apparatus also not shown. A portion of theouter surface of the pickup drum 41 is in snug contact with a continuousconveyor belt 44 made of electrically conductive but non-magnetic andnon-magnetizable material, e.g., stainless steel. The belt 44 is incontact. e.g., by brush contacts, with a source of electric power.conventionally of direct current, all not shown. This conveyor belt 44is also in snug contact with a conveyor drum 45.

The conveyor drum 45 is supported by a hub 46 on a stationary shaft 47.Attendant support apparatus for the conveyor drum 45 is also not shown.Either the conveyor drum 45 or the pickup drum 41 or both, may beconnected through drive means to a power source providing rotationalmovement. As shown in FIG. 3,

both drums 45 and 41 rotate clockwise, thereby, in operation, providingcontinuous rotation of the conveyor belt 44 in a generally clockwisemanner.

The pickup drum 41 houses an interior stationary magnet 48 and further,this drum 41 is in part immersed in a bath 49 of electrocoat paint. Theimmersion of the drum 41 into the bath 49 also results in the immersionof a portion of the conveyor belt 44 into the bath 49. Also immersed inthe bath 49 are freshly en tering parts 51 feeding from a source notshown. These parts 51 enter the bath 49 and move along the bottomsurface of a holding tank 52 containing the bath 49 of electrocoatpaint. The tank 52 is connected by means not shown to serve as theelectrode providing an electric charge to the parts 51. Subsequently,coated parts 53 are attracted onto the conveyor belt 44 by the magnet48. The coated parts traveling on the conveyor belt 44 between thepickup drum 4] and conveyor drum 45 may pass over a demagnetizer 54;continuing on, the coated parts 53 are gravity fed from the conveyorbelt 44 and fall onto a removal conveyor 55 for transportation away fromthe conveyor drum 45 and typically to operations as have been mentionedhereinabove. When no demagnetizer 54 is present between the drums 41 and45, the coated parts 53 on the removal conveyor 55 pass over ademagnetizer 56. During continued rotation, the portion of the conveyorbelt 44 continuing on around the conveyor drum 45 is then reintroducedinto the bath 49.

Referring to FIG. 4, a first drum 6] is equipped in a manner as has beendescribed for the drum 4 in FIG. 1. Thus, in part, it is mounted on ahub 62 for rotational movement around a stationary shaft 63. Within thefirst drum 61 is a stationary magnet 64 positioned by means of supportmembers not shown. The magnet 64 is in the lower zone of the first drum61 and is spaced away from the interior shell surface of the drum 61.The bottom portion of the drum 61 is slightly immersed in liquidtreating composition 65 contained in a holding tray 66. At the left handportion of the holding tray 66, fresh parts feeding from a source notshown enter the liquid treating composition 65 and become submersedtherein under the drum 61.

Closely adjacent to this first drum 61 but at the right hand side of thedrum 61 is an intermediate conveyor 67. That is, the conveyor 67 isspaced intermediately between the first drum 61 and a second drum 71.Submerged articles 68 that move out of the liquid treating composition65 on the rotating first drum 61, reach a zone where gravitational forceovercomes the magnetic force of the stationary magnet 64. As a result,the treated articles 69 fall onto the intermediate conveyor 67;thereafter, they may be conveyed over a demagnetizer 72.

The treated articles 69 next are conveyed into a bath 76 of electrocoatpaint. The paint bath 76 is contained in a holding tray 75 that servesas one electrode, and hence the bath functions as has been describedhereinbefore for FIG. 2. Thus, the other electrode 74 is slightlyimmersed in the bath 76 and spaced apart from the bottom of the holdingtray 75. Submersed and treated parts 73 are coated in the bath 76 asthey move under the electrode 74 along the tray 75.

Also immersed in the bath 76 is the lower portion of the second drum 71.As was the case with the first-drum 61, the second drum 71 is mounted bya hub 77 about a stationary shaft 78 and has additional, attendantapparatus as discussed hereinabove with similar such drums. Housed inthe second drum 71 is a stationary magnet 79. Treated parts 73 that havebecome coated parts 81 in the bath 76, are conveyed out of the bath 76under the influence of the stationary magnet 79 on the outer face of thesecond drum 71. These coated parts 81 fall by gravitational force onto aremoval conveyor 82 whereby the coated parts 81 are conveyed over ademagnetizer 83 to subsequent operation.

In operation, as an example, articles that have been surface coated witha phosphate coating and subsequently water rinsed, may then be immersedin an aqueous solution 65 of chromic acid. The subsequently rinsed parts69 are then brought by the drum 61 out of this solution 65 and depositedon the intermediate conveyor 67; thereon they may be slowly carriedunder infra red lamps or through an oven or the like for drying. Thedried parts then leave the intermediate conveyor 67 and are immersed ina bath 76 of electrocoat paint.

In like manner for a sequence of pre-treatments, a first drum 61 may beused, with attendant apparatus, to prepare the initial phosphate coatingon the parts. In this instance, the fresh parts will be introduced intoan aqueous phosphate coating bath 65. Resulting phosphate coated parts69 may then be transported. as on a woven, porous intermediate conveyor67 that will permit rinsing of the parts on the conveyor 67.

The subsequently coated and rinsed parts can be introduced through asecond treating operation, e.g., the above mentioned chromic acid rinsewhereby the phosphate coated parts leaving the intermediate conveyor 67are fed into the chromic acid treating bath 65 and proceed as abovedescribed. Where an extended residence time for parts in a liquidcomposition is desired, such can be achieved, for example, by adjustmentof equipment sizing. The advantages of the above sequences, includingthe extended sequence of first phosphate coating, subsequently chromicacid rinsing, and then painting has been disclosed in U.S. Pat. No.3,454,483. Similarly, a desirable sequence of coating steps, including afinal application of electrocoat paint, which sequence can be handled byapparatus such as depicted in FIG. 4, has been disclosed in U.S. Pat.No. 3,616,392.

When many small metallic articles are coated at the same time, adjacentarticles may be in close contact that is not easily broken. Thisphenomena is sometimes referred to as nesting". Nesting or otherinter-part contact can lead to entrapment of air bubbles between parts,resulting in small unpainted patches or holidays in the overall paintedsurface. It is thus desirable to cause some movement between the partsduring the coating operation as has been underscored in U.S. Pat. No.3,728,247. In view of this, and referring to FIG. 5, uncoated parts 91feeding from a source not shown enter a coating bath 92 on a feedconveyor 93. The coating bath 92 is maintained in a large holding tray94.

The feed conveyor 93, powered by attendant drive means, not shown, alsoserves as an electrode; thus, the electric charge given to the uncoatedparts 91 is through the feed conveyor 93. It may be connected in aconventional manner, e.g. brush contacts, to a source of electricalenergy, all not shown. The feed conveyor 93 may be formed, for example,of non-magnetic and non-magnetizable, but electrically conductive wovenstainless steel. The uncoated parts 91 travelling on the feed conveyor93 pass under an immersed electrode 95, submersed in the coating bath 92directly above a zone of the path of travel of the feed conveyor 93 andhaving an upper insulating layer 90.

Resulting coated parts 96 travelling at first deeper into the coatingbath 92 on the feed conveyor 93 come under the influence of a magneticfield emanating from a stationary magnet 97. This stationary magnet 97is housed in an intermediate drum 98that is supported by a hub 99 ona-stationary shaft 101. This arrangement of drum 98, hub 99 andstationary shaft 101 is supported by bearings and driven by attendantdrive means, all not shown. The drum 98 is intermediate between the feedconveyor 93 and a second coating conveyor 102.

Coated parts 96 under the influence of the stationary magnet 97 areattracted and held on the outer surface of the intermediate drum 98. Asthe drum 98 rotates, these coated parts 96 eventually move beyond themagnetic field; thereafter, while outside the coating bath 92 and underthe influence of gravity, they slide down the outer face of theintermediate drum 98. Since the drum 98 during its rotation is partlyimmersed in the coating bath 92, the outer surface of the drum 98becomes wet with coating bath liquid. The coated parts 96 thereforeslide, in a region of the drum 98 above the second coating conveyor 102,across a wetted surface.

As the coated parts 96 slide free from the wet surface of the drum 98they re-enter the coating bath 92, which operation acts to enhanceseparation of adjacent parts and the removal of previously entrapped airbubbles. ln falling, the coated parts 96 land on the second coatingconveyor 102 powered by attendant drive means, not shown. The secondcoating conveyor 102 is given an electric charge; thus, through theconveyor 102 the charge is conducted to the coated parts 96, and all byconventional means and through a conventional power source, not shown.On the second coating conveyor 102, the coated parts 96 move under asubsequent immersed electrode 103 having an upper insulating cover 100.This passage under the subsequent electrode 103 serves to continue thecoating of the parts 96 after drum-induced separation. The resultingfinally coated parts 104 are then moved along the second coatingconveyor 102 and come under the influence of a pickup drum stationarymagnet 105. The pick-up drum 106 housing such magnet 105, is mounted ona hub 107 for rotational movement around a stationary shaft 108 and isfurther equipped in a manner as has been referred to for the drum 4 inFIG. 1.

As the pickup drum 106 rotates, the finally coated parts 104 held on thesurface of the drum 106 by the stationary magnet 105, move initially outof the coating bath 92. As rotatation continues, these parts 104 soonleave the influence of the magnetic field and, under gravitationalinfluence, fall from the drum 106 onto a removal conveyor 109. The parts104 are then conveyed on the removal conveyor 109 over a demagnetizer111 and typically on to a subsequent rinse.

As a variation of apparatus that can provide some inter-part movementduring the coating operation, and now referring to FIG. 6, parts 121ready for coating and feeding from a source not shown enter a coatingbath 122 on a feed conveyor 123. The coating bath 122 is maintained in alarge holding tank 124. 7

As used herein, all of the holding tanks are typically connected byrecirculating means not shown to separate storage tanks, also not shown.By this arrangement, fresh coating liquid is supplied to the holdingtanks; and, in the separate storage tank, which may be equipped withattendant cooling equipment, the coating liquid is typically agitatedand filtered and otherwise adjusted, e.g., pH adjustment, vto providefor the desired characteristics of the electrocoat paint in the holdingtank.

The feed conveyor 123, powered by attendant drive means, not shown, alsoserves as an electrode; thus, the electric charge given to the uncoatedparts 121 is conducted through this conveyor 123. It may be connected ina conventional manner e.g.', brush contact to a source of electricalenergy, all not shown. The feed conveyor 123 can thus be of likeconstruction as the feed conveyor 93 of FIG. 5. The parts 121 travelingon the feed conveyor 123 pass under an immersed electrode 125 having anupper insulating layer 120, and all being submerged in the coating bath122 directly above a zone of the path of travel of the feed conveyor123.

Resulting coated parts 126 traveling at first deeper into the coatingbath 122 come under the influence of a magnetic field that orginatesfrom a stationary magnet 127. This magnet 127 is housed in anintermediate drum 128. The drum is supported by a hub 129 on astationary shaft 131. This arrangement of drum 128, hub 129 andstationary shaft 131 is supported by bearings and driven by attendantdrive means, all not shown. The drum 128 is intermedite between the feedconveyor 123 and a second coating conveyor 132.

Coated parts 126 under the influence of the stationary magnet 127 areattracted and held on the outer surface of the intermediate drum 128. Asthe drum 128 rotates, these coated parts 126 eventually move beyond themagnetic field; thereafter, while outside the coating bath 122 and underthe influence of gravity, they slide down the outer face of theintermediate drum 128. Since this drum 128 during its rotation is partlyim-' mersed in the coating bath 122 the outer surface of the drum 128becomes wet with coating bath liquid. The coated parts 126 thereforeslide, in a region of the drum 128 above the second coating conveyor132, across a wetted surface.

As the coated parts 126 slide free from the surface of the drum 128,they re-enter the coating bath 122. This sliding and falling operationacts to enhance separation of adjacent parts and the removal ofpreviously entrapped air bubbles. ln falling, the coated parts 126 landon the second coating conveyor 132 powered by attendant drive means, notshown. This second coating conveyor 132 is given an electric charge;hence, through the conveyor 132 the charge is conducted to the parts 126coming in contact with the conveyor 132, and all by conventional meansand through a conventional power source, not shown. On the secondcoating conveyor 132, the re-immersed parts 133 move under a subsequentimmersed electrode 134 that has an upper insulating cover 136. Thispassage under the subsequent electrode 134 serves to continue thecoating of the re-immersed parts '133 following drum-induced separation.

The resulting finally-coated parts 135 are then moved along the secondcoating conveyor 132 and are thereby carried out of the coating bath 122owing to the inclined angle of the second coating conveyor 132. Thefinally coated parts 135 move out of the coating bath 122 for furtheroperation, e.g., passage on a removal conveyor over a de-magnetizer andpossibly to a sequence of rinse operations prior to subsequent curing.

Curing as used herein can include, for example, baking as under infrared lamps or forced and heated air drying, or other useful operation toaffect typically polymerization of coating constituents such asradiation curing.

Another procedure for effecting the simultaneous coating of a number ofsmall parts while feeding the parts from deleterious adjacent inter partcontact uses an inclined drum. Thus, and referring to FIG. 7, parts 141ready for coating slide down a feed chute 142, that may be preferablywetted with coating composition as from an overhead spray applicator. Asthe parts 141 continue down the feed chute 142 they become submersed ina coating bath 143 contained in a holding tank 144. Upon leaving thefeed chute 142, the uncoated but submersed parts 141 are deposited intoa cylindrical drum 145. This drum 145 has mounting means and is drivenin rotation by attendant drive means, all not shown.

The cylindrical drum 145 also serves as an electrode. Hence, electriccharge is given to the deposited and uncoated parts 141 through thecylindrical drum 145. It is connected in conventional manner such asthrough brush contacts to a source of electrical energy, all not shown.The interior of the drum 145 is equipped with a helical track 146. Thus,as the drum 145 revolves, the submerged parts 141 move upwardly in thedrum 145, typically in groups of parts, by means of the helical track146.

As rotation of the drum 145 continues, the parts 141 travel underneathan immersed electrode 147 spaced within the drum 145 but aparttherefrom. During conveyance upwardly within the drum 145 and under theimmersed electrode 147 the parts 141 thereby become coated. Further,owing to movement within the drum 145, the parts are retained free fromdeleterious interpart contact.

Resulting coated parts 148 emerge from the drum 145 showing highlydesirable uniform coating. These coated parts 148 emerging from the drum145 are maintained in the coating bath 143. This submergence in thecoating bath 143 is maintained by providing for the coated parts 148leaving the drum 145 to come under the influence of a stationary magnet149.

The stationary magnet 149 is housed in a cylindrical drum 151 that issupported by a hub 152 on a stationary shaft 153. This arrangement ofdrum 151, hub 152 and stationary shaft 153 is supported by bearings anddriven by attendant drum drive means, all not shown.

Coated parts 148 under the influence of the stationary magnet 149 areattracted and held on the outer surface of the drum 151. As the drum 151rotates, these coated parts 148 leave the coating bath 143 and continueon the drum until they eventually move beyond the magnetic field.Thereafter, under the influence of gravity. the coated parts 148 slidedown the outer surface ofthe drum 151 and onto a removal conveyor 154.Since the drum 151 during its rotation is partly immersed in the coatingbath 143, the outer surface of the drum 151 becomes wet with coatingbath liquid. The coated parts 148 therefor slide onto the removalconveyor 154 from a wetted surface of the drum 151. On the removalconveyor 154 the coated parts 148 are carried away from the drum 151 andover a de-magnetizcr 155 to further typical operation as hereinabovedescribed.

Referring again to FIG. 1, the chute 8 can be fabricated from stainlesssteel, as can the holding tank 9, and the fresh articles 7 may be wettedwith coating bath liquid, prior to entering into the bath 11, as byspray application of liquid overhead of the chute 8. Such sprayapplication can further be preferably utilized in all such feeds, e.g.,overhead of the feed chute 142 of FIG. 7. It is also contemplated thatthe holding tank 9 in FIG. 1 may serve as an electrode thereby chargingthe bath 11 and permitting removal of the electrode 16. It is furthercontemplated that in such arrangement, or in any such assembly describedherein of apparatus wherein a tank or tray serves as an electrode, e.g.,an anode for anodically deposited paints, that it may be desirable tolimit the charged area of the tank. To this end, an insulated coating isapplied to pre-determined portions of the interior surfaces of the tank,resulting in regions that will not carry an electrical charge to thebath or to articles in the tank. Sucn insulated coating will therebyserve to reduce the inner surface of the container to a zone more nearlyequating to the zone of the cathode area exposed to the coating liquidin the tank. For the insulating layer 17 as depicted in FIG. 1, such canbe a perforated nylon screen for protecting the electrode 16.

In FIG. 2, the fresh parts 21 feeding into the bath 22 may fall onto acoating conveyor, rather than at the bottom of the tank 23, such as thesecond coating conveyor 102 of FIG. 5. The parts 21 will then be movedalong the coating conveyor and coated as they come under the electrode24. Resulting coated parts 25 leaving the coating conveyor are thenattracted by the magnet 26 onto the pick-up drum 27. Such operation isalso applicable for the submersed and treated parts 73 in FIG. 4. Foreither the electrode 24 in FIG. 2 or the electrode 74 of FIG. 4 it ispreferred that each have an insulating cover, e.g., a solid plexiglasscovering over the electrode, to guard against accidental electricalshort circuits as might arise from objects inadvertently falling intothe tanks 23 and 75 and contacting such tanks and the electrodes 24 and74. In FIG. 3, it is contemplated to extend the distance between thepickup drum 41 and the conveyor drum 45, while eliminating thede-magnetizer 54. In this case, the coated parts 53 traveling on theconveyor belt 44 can proceed through one or more rinsing steps, as forexample where the conveyor belt 44 is a porous, woven stainless steelbelt. Thus the coated parts 53 may even proceed to a curing step priorto removal from the conveyor belt 44 by gravity feeding off the belt 44around the conveyor drum 45. It is also contemplated in FIG. 3 to feedfresh parts into the bath 49 down a chute. And preferably, to feed freshparts down a chute, e.g., the feed chute 142 of FIG. 7 wherein freshbath liquid is applied onto the parts and onto the chute to providewetted parts feeding into the bath 49.

In FIG. 5, the intermediate drum 98 can be completely immersed in theliquid paint in the coating bath 92. Further, a stationary magnet 97within the intermediate drum can have field shaping poles, as discussedmore particularly hereinabelow, to enhance inter-part movement of thecoated parts 96 as they are rotated on the outer surface of theintermediate drum 98. Field shaping poles for stationary magnets arecontemplated where parts under the influence of the magnetic field arealso in contact with coating liquid. For example, for the stationarymagnet 12 in FIG. 1 or the stationary magnet 127 in FIG. 6., Moreover,the feed conveyor 93 in FIG. 5, as well as for all such conveyorsdepicted in the drawings which carry articles thereon that also arecoated thereon, such conveyors can be in assembly with deplatingelectrodes. For the feed conveyor 93 this can be facilitated bypositioning an electrode under the conveyor, i.e., adjacent the path oftravel of the portion of the conveyor 93 exiting the coating bath 92.This lower electrode is electrically charged with the same charge on theconveyor 93 entering the bath 92. The result is to change the charge onthe conveyor 93 in the zone of the lower electrode and thereby removepaint from the conveyor 93 as it leaves the bath 92. Subsequently, theuncoated parts 91 feeding on to the conveyor 93 as it enters the bath 92are feeding on to a fresh, uncoated surface of the conveyor 93.

It is also contemplated in FIG. to provide that the pick-up drum 106 bein combination with a conveyor drum such as the conveyor drum 45 in FIG.3. The conveyor drum would be spaced apart from the conveyor drum 106,with a connecting conveyor belt. Thus, in FIG. 5 as in FIG. 3, thefinally coated parts 104 would be moved along a conveyor belt beyond thecoating bath 92, then typically proceed through one or more rinsingsteps and even a subsequent curing operation prior to removal from theconveyor belt. It may be also desirable in FIG. 5 to replace the feedconveyor 93 and immersed electrode 95 with a cylindrical feed drumhaving an interior helical track, such as the cylindrical drum 145having the interior helical track 146 as depicted in FIG. 7. However,for FIG. 5 such drum would be gently canted to permit gradual immersionof the parts 91 entering the coating bath 92. Resulting coated parts 96could then be deposited on a more fully immersed intermediate drum 98upon leaving the cylindrical feed drum.

It is further contemplated that such feed drum arrangement will also beuseful in FIG. 6 for replacing the feed conveyor 123 plus immersedelectrode 125 apparatus. In a like manner, such drum and helical trackcan be used, in FIG. 6, for replacing the second coating conveyor I32and subsequent immersed electrode 134. In this replacement however,there is provided an intermediate chute to transmit the re-immersedparts 133 leaving the intermediate drum 128 down into the interiorportion of the cylindridal drum. Furthermore, the finally coated parts135 will be transported out of the coating bath 122 with an additionaldrum such as with the drum 151 of FIG. 7. Also in FIG. 6 the feedconveyor 123, as well as with other feed conveyors such as the feedconveyor 93 of FIG. 5, may be arranged with overhead spray applicatorsto wet parts 121 prior to immersion of the parts into the coating bath122. Such pre-entry wetting with electrocoating liquid serves to enhanceperformance of the bath as well as to retard holidays caused byentrapped air bubbles.

In carrying out the coating operations, the electrodes that aregenerally depicted, such as the immersed electrode 125 and subsequentimmersed electrode 134 of FIG, 6, are conventionally grid electrodes,sometimes termed standoff electrodes that provide an electrical chargeto a localized portion of the coating bath, and are typically coarsestainless steel wire mesh,

In FIG. 7, such wire mesh construction can also serve for the immersedelectrode 147; but, the electrode 147 is typically arcuate in crosssection in conformance with the cylindrical shape of the drum 145. Suchelectrode 147 is preferably extended essentially to the end zone of thedrum wherein the coated parts 148 are leaving the drum 145. It is alsopreferable that such cylindrical drum 145 be provided with a multitudeof minute perforations, insufficient to permit passage of the coatedparts 148 therethrough or to substantially impair coating thereof butsufficient to augment free passage of coating liquid within the drum145.

Coated parts emerging from the coating baths, e.g., the coated parts 13of FIG. 1 or coated parts 25 of FIG. 2, may typically fall onto oneanother as they are being processed onto the removal conveyors. Thisinter-part jostling may result in tiny surface nicks but these tend tobe covered in subsequent curing since the deposited coating will flowslightly during the curing process. Where the removal conveyors, e.g.,removal conveyor 14 in FIG. 1 or removal conveyor 31 in FIG. 2 willtransmit the parts, conventionally after rinsing, to curing operation asto a bake oven, such conveyors may be wire-mesh conveyor belts that arecoated with nonstick'resin coatings. This enhances freedom from stickingof the coated parts to the conveyor during the curing operation. Forthis use, resins such as polymerized tetrafluoroethylene, have met withcommercial acceptance.

The rotatable drum or cylindrical shell housing an interior stationarymagnet can be any of such apparatus that are generally well known in themagnetic separation art. An example of the drum type magnetic separatorthat can or has been used in the practice of this invention is shown forexample in U.S. Pat. No. 2,950,008. In such patent the drum envelopspowerful electromagnets which, for the purposes of the presentinvention, may be powered by alternating or direct current.Additionally, permanent magnets within the drum are particularlyserviceable. Furthermore, it is contemplated to use a drum and magnetarrangement such as disclosed in US. Pat. No. 3,489,280. The magnets asdisclosed therein have field shaping poles whereby material which ismagnetically attracted onto the exterior face of the drum can becarried, by rotation of the drum, through a series of alternatingpolarity magnetic fields. The result is a rotation of the material onthe surface of the drum, and the serviceability of this feature has beenmentioned hereinabove.

It is further contemplated to supply the outer surface of a drum, as forexample the outer surface of the pickup drum 27 of FIG. 2, with anapparatus that facilitates releasing the coated articles away from theface of the drum. As an example, rod or flap members extendinglongitudinally across the drum face, such members being further spacedapart one from the other, can

serve to enhance such release. On the pickup drum 27 in FIG. 2 they willserve to guide away from the surface of the drum 27 the coated parts 25when these parts 25 begin to slide downwardly on the wet face of thedrum 27. The longitudinal rod or flap members also will become wetted byimmersion during rotation of the drum 27. Similar guiding action may beobtained by other apparatus, e.g., a rippled screen extending across thecircumference of the drum face and longitudinally across such face.

The initial coating apparatus of FIG. 4, including the first drum 61,may be used for applying the surface of metal articles such treatmentsas are conventionally used, or any that are contemplated for use. priorto the application of electrocoat paint. Such apparatus will be usefulwith liquids that would otherwise be applied by immersion or sprayapplication techniques to the metal articles. Thus, the apparatusincluding the first drum 61, or similar apparatus preceding theapparatus including the first drum 61, may be used for operationsincluding cleaning or rinsing, etching, coating or combinations of suchoperations. And by use of the term treating" herein, such use isintended to include these operations. Moreover. metallic objects orarticles that have magnetic susceptibility and are typically dip orspray treated are represented by metal fasteners including nuts, bolts,screws and clips, and such preferably that have a ferrous substrate suchas iron or steel including magnetizable stainless steel, but alsoincluding galvanized steel, chromeplated steel, and other coatedsubstrates.

Parts for coating, such as the articles 7 in FlG. l, are typicallyfreshly cleaned parts as may be obtained by degreasing with knownagents, for instance, agents containing metasilicate, caustic soda,carbon tetrachloride, trichloroethylene, and the like. Such parts, e.g.,grade 8 bolts which are 1 1/16 inches long by one-fourth inch indiameter at the threaded end and have seven-eighths inch of threading onthe shaft topped by a inch smooth shaft section that terminates in thebolt head, are coated in conventional manner with a pre-paint primer.

The primer is water-based and contains 300 grams per liter (g/l) of zincflake and 40 g/l of chromic acid. Further, the composition is preparedwith 3 milliliters per liter (ml/l) of wetter and 21 volume percent ofdipropylene glycol. The wetter is a nonionic, modified polyethoxy adducthaving a viscosity in centipoises at 25 C of 180 and a density at 25 Cof 8.7 pounds per gallon. The cleaned bolts are coated by placing in awire basket and dipping the basket into the coating composition,removing the basket and draining excess composition herefrom with a mildshaking action and then immediately baking in a hot air convection ovenat a substrate temperature of about 450 F for about l minutes. The partsare then ready for the application of electrocoat paint. In suchoperation, the electrocoat paint used is a commerical water-based,blackpigmentcd polyester-based paint. It is anodically deposited with animpressed voltage of 100-150 volts for a duration of about 45 seconds.For this, and referring to FIG. I, the pre-coated parts 7 are carefullygravity-fed down a metal tray, e.g., the chute 8. As these parts 7 comedown the feed tray 8 and are initially submersed in the bath ll of theelectrocoat paint, the stationary interior magnet 12 of the magneticdrum 4 attracts the falling parts 7 directly on to the outer surface ofthe magnetic drum 4.

The magnetic drum measures 12 inches in length along the shaft or axisabout which the drum rotates. The drum is about 13 inches in diameterand is equipped with rim elements at each end projecting upwardly fromthe drum face approximately one-half inch and around the entire extentof the circumference of the drum, thereby providing the end of the drumwith an about 14-inch diameter. The drum, a model DPC- 1212,manufactured by the Bux-Shrader Company, rotates in a counter-clockwisemanner. The drum is geared to rotate at a rate of about 0.25 revolutionper minute. It serves as the anode in the painting operation by means ofbrush contacts on each of the drum rims. Across the face of the drum andparallel to the drum shaft axis are six aluminum flaps.

These flaps are placed across the face of the drum at essentially equaldistance one from the other and in cross section, have a shape like alazy h; the flaps are affixed to each rim member by metal bands aroundthe periphery of the rim. The flaps are positioned such that coatedparts 13 slipping downwardly on the face of the drum 4 will contact theleaning, longer member of the lazy h portion of the flap and thereby, asslipping continues, will be deflected away from the continuouslyrotating drum 4. The interior magnet within the drum is a stationarypermanent magnet that holds the parts 7 securely on the face of the drum4 during rotation through the paint 11. During such rotation, the parts7 become anodically charged by the drum 4 and pass by the cathode 16,thereby receiving the deposition of paint. in operation, the cathode 16has a perforated nylon screen insulator 17 to guard against electricalshort circuits.

Thereafter, as the drum 4 continues rotation, the coated parts 13 areconveyed in an arcuate path of travel out of the paint bath 11. As suchparts 13 are overcome by gravitational forces, they slip downwardlyacross the face of the drum 4 and during this are in contact with thewet paint film on the face and on the flaps of the drum 4 which film hasbeen deposited during the continuous rotation of the drum 4 through thebath ll. Thereafter, these coated parts 13 fall onto the conveyor 14 andare transported then to a rinsing operation. After rinsing, and thenbaking, which augments flowing of the deposited paint over the contactpoints of the parts 7 with the drum 4 that have resulted during thecoating operation, the subsequent painted articles are dry to the touchand, under visual inspection, have the appearance of articles ready forcommercial use, e.g., under corrosive conditions.

I claim:

1. ln apparatus adapted for establishing and interrupting contactbetween I a plurality of discrete, magnetically-attractable andelectrically-conductive metallic articles of manufacture andelectrically deposited electrocoating composition, whereby applicatormeans serves to bring said plurality of articles into contact with theelectrocoating composition, and wherein an electrode of said applicatormeans is adapted to convey an electrical charge to said articles incontact with electrocoating composition, while transporting means,adapted to carry wet, surfacecoated articles, operates to carry said wetarticles away from said coating composition, the improvement in adaptingsaid apparatus for the coating of a plurality of articles of non-smoothconfiguration which comprises:

A. magnet means spaced away from said electrode that conveys electricalcharge to said articles in contact with electrocoating composition, saidmagnet means being arranged in close proximity to the path of travel ofsaid articles in contact with the electrocoating composition, and beingadapted to act on wet, coated articles and thereby influence their pathof travel; said magnet means cooperating with B. rotatable meansproximate to said magnet means;

and having,

C. a non-magnetic, rotatable and continuous face element spaced apartfrom said magnet means and in continuous exposure to the electrocoatingcomposition, said face element being adapted to provide movement of aplurality of wet, coated articles within the electrocoating composition,and away from said applicator means, with said wet and coated articlesbeing attracted into contact with said face element while said articlesare under the influence of the magnetic field.

2. The apparatus of claim 1 wherein said applicator means includes atank member for retaining a bath of said electrocoating composition incontact with the articles.

3. The apparatus of claim 1 wherein said rotatable means includes arotatable drum.

4. The apparatus of claim 3 wherein said magnet means includes at leastone interior magnet within said drum and said interior magnet has anarcuate surface in concentric relationship spaced apart from said drum.

5. The apparatus of claim 3 wherein said applicator means includeselectrocoating supply means adapted to provide sufficient coatingcomposition for partial immersion of said rotatable drum in said coatingcomposition.

6. The apparatus of claim 1 wherein said rotatable means includes atleast two rotatable members and said members have a continuous,non-magnetic belt around same.

7. The apparatus of claim 1 further characterized by demagnetizing meansspaced away from said rotatable means and proximately adjacent to thepath of travel of coated articles leaving said rotatable means.

8. Apparatus constructed to provide electricallyinduced, contemporaneousdeposition of a coating from a liquid electrocoating bath upon aplurality of discrete, electrically-conductive andmagneticallyattractable metallic articles, and being adapted for theelectrocoating of said articles of non-smooth configuration, whichapparatus comprises:

A. a tank adapted to retain a bath of liquid electrocoating material;

B. delivery means constructed for feeding a plurality of said metallicarticles into the tank and thereby into submersion in a coating zone ofliquid material;

C. electrical means adapted to provide a flow of electrical energythrough the coating zone of the bath and through electrically conductivearticles located therein, resulting in coated metallic articles therein;

D. magnet means spaced away from said electrical means, but beingarranged in close proximity to the metallic articles, said magnet meanshaving sufficient field strength to influence the locus of said articlesin said portion of the zone; said magnet means cooperating with,

E. rotatable means proximate to said magnet means;

and having F. a non-magnetic, rotatable and continuous face elementspaced apart from said magnet means and adapted to be in continuousexposure to said electrocoating composition, which face elementcooperates with said magnet means and in rotataion provides movement ofwetted articles attracted into contact with said face element while saidarticles are under the influence of the magnetic field.

9. The apparatus of claim 8 wherein said rotatable means includes arotatable drum.

10. The apparatus of claim 9 wherein said magnet means includes at leastone interior magnet within said drum and said interior magnet has anarcuate surface in concentric relationship spaced apart from said drum.

11. The apparatus of claim 9 wherein said rotatable drum serves as anelectrode in the means providing a flow of electrical energy through thecoating zone of the bath.

12. The apparatus of claim 8 wherein said rotatable means includes atleast two rotatable members and said magnetic belt around same.

13. The apparatus of claim 8 wherein said rotatable means is adapted tointerrupt continuing contact between coated articles and said bath andto convey wet, coated articles away from the bath.

14. The apparatus offclaim 8 further characterized by demagnetizingmeans spaced away from said rotatable means and proximate to the path oftravel of wet articles leaving said rotatable means.

15. The apparatus of claim 8 further characterized by conveying meansconstructed and arranged to carry wet articles away from said rotatablemeans.

16. The apparatus of claim 15 further characterized by rinsing means towhich wet articles are transported on said conveying means.

17. The apparatus of claim 8 wherein said tank is an electrode in themeans providing electrical energy through the coating zone of said bathand the flow of,

electrical energy thereto is a direct current flow.

1. In apparatus adapted for establishing and interrupting contactbetween a plurality of discrete, magnetically-attractable andelectrically-conductive metallic articles of manufacture andelectrically deposited electrocoating composition, whereby applicatormeans serves to bring said plurality of articles into contact with theelectrocoating composition, and wherein an electrode of said applicatormeans is adapted to convey an electrical charge to said articles incontact with electrocoating composition, while transporting means,adapted to carry wet, surface-coated articles, operates to carry saidwet articles away from said coating composition, the improvement inadapting said apparatus for the coating of a plurality of articles ofnon-smooth configuration which comprises: A. magnet means spaced awayfrom said electrode that conveys electrical charge to said articles incontact with electrocoating composition, said magnet means beingarranged in close proximity to the path of travel of said articles incontact with the electrocoating composition, and being adapted to act onwet, coated articles and thereby influence their path of travel; saidmagnet means cooperating with B. rotatable means proximate to saidmagnet means; and having, C. a non-magnetic, rotatable and continuousface element spaced apart from said magnet means and in continuousexposure to the electrocoating composition, said face element beingadapted to provide movement of a plurality of wet, coated articleswithin the electrocoating composition, and away from said applicatormeans, with said wet and coated articles being attracted into contactwith said face element while said articles are under the influence ofthe magnetic field.
 2. The apparatus of claim 1 wherein said applicatormeans includes a tank member for retaining a bath of said electrocoatingcomposition in contact with the articles.
 3. The apparatus of claim 1wherein said rotatable means includes a rotatable drum.
 4. The apparatusof claim 3 wherein said magnet means includes at least one interiormagnet within said drum and said interior magnet has an arcuate surfacein concentric relationship spaced apart from said drum.
 5. The apparatusof claim 3 wherein said applicator means includes electrocoating supplymeans adapted to provide sufficient coating composition for partialimmersion of said rotatable drum in said coating composition.
 6. Theapparatus of claim 1 wherein said rotatable means includes at least tworotatable members and said members have a continuous, non-magnetic beltaround same.
 7. The apparatus of claim 1 further characterized bydemagnetizing means spaced away from said rotatable means andproximately adjacent to the path of travel of coated articles leavingsaid rotatable means.
 8. APPARATUS CONSTRUCTED TO PROVIDEELECTRICALLY-INDUCED CONTEMPORANEOUS DEPOSITION OF A COATING FROM ALIQUID ELECTROCATING BATH UPON A PLURALITY OF DISCRETE,ELECTRICALLY-CONDUCTIVE AND MAGNETICALLY-ATTACHTABLE METALLIC ARTICLESAND BEING ADAPTED FOR THE ELLECTROCOATING OF SAID ARTICLES OF NONSMOOTHCONFIGURATION, WHICH APPARATUS COMPRISES: A. A TANK ADAPTED TO RETAIN ABATH OF LIQUID ELECTROCOATING MATERIAL, B. DELIVERY MEANS CONSTRUCTEDFOR FEEDING A PLURALITY OF SAID METALLIC ARTICLES INTO THE TANK ANDTHEREBY INTO SUBMERSION IN A COATING ZONE OF LIQUID MATERIAL, C.ELECTRICAL MEANS ADAPTED TO PROVIDE A FLOW OF ELECTRICAL ENERGY THROUGHTHE COATING ZONE OF THE BATH AND THROUGH ELECTRICALLY CONDUCTIVEARTICLES LOCATED THEREIN, RESULTING IN COATED METALLIC ARTICLES THEREIN,D. MAGNET MEANS SPACED AWAY FROM SAID ELECTRICAL MEAN, BUT BEINGARRANGED IN CLOSE PROXIMITY TO THE METALLIC ARTICLES, SAID MAGNET MEANSHAVING SUFFICIENT FIELD STRENGTH TO INFLUENCE THE LOCUS OF SAID ARTICLESIN SAID PORTION OF THE ZONE, SAID MAGNET MEANS COOPERATING WITH, E.ROTATABLE MEANS PROXIMATE TO SAID MAGNET MEANS, AND HAVING F. ANON-MAGNETIC, ROTATABLE AND CONTINUOUS FACE ELEMENT SPACED APART FROMSAID MAGNET MEANS AND ADAPTED TO BE IN CONTINUOUS EXPOSURE TO SAIDELECTROCOATING COMPOSITION, WHICH FACE ELEMENT COOPERATES WITH SAIDMAGNET MEANS AND IN ROTATION PROVIDES MOVEMENT OF WETTED ARTICLESATTRACTED INTO CONTACT WITH SAID FACE ELEMENT WHILE SAID ARTICLES AREUNDER THE INFLUENCE OF THE MAGNETIC FIELD.
 9. The apparatus of claim 8wherein said rotatable means includes a rotatable drum.
 10. Theapparatus of claim 9 wherein said magnet means includes at least oneinterior magnet within said drum and said interior magnet has an arcuatesurface in concentric relationship spaced apart from said drum.
 11. Theapparatus of claim 9 wherein said rotatable drum serves as an electrodein the means providing a flow of electrical energy through the coatingzone of the bath.
 12. The apparatus of claim 8 wherein said rotatablemeans includes at least two rotatable members and said magnetic beltaround same.
 13. The apparatus of claim 8 wherein said rotatable meansis adapted to interrupt continuing contact between coated articles andsaid bath and to convey wet, coated articles away from the bath.
 14. Theapparatus of claim 8 further characterized by demagnetizing means spacedaway from said rotatable means and proximate to the path of travel ofwet articles leaving said rotatable means.
 15. The apparatus of claim 8further characterized by conveying means constructed and arranged tocarry wet articles away from said rotatable means.
 16. The apparatus ofclaim 15 further characterized by rinsing means to which wet articlesare transported on said conveying means.
 17. The apparatus of claim 8wherein said tank is an electrode in the means providing electricalenergy through the coating zone of said bath and the flow of electricalenergy thereto is a direct current flow.